If you've seen the NVIDIA SHIELD handheld gaming device working with streaming PC gaming in a home network, you know how it works - potentially - with Steam's Big Picture mode. Now Valve is taking this sort of functionality and pushing it to many devices. At the moment, they're calling this "Steam in-home streaming" a beta, and they're releasing it to developer partners and other odd testers this week.
Though not implicitly tied to SteamOS, this functionality is meant to be part of the full Steam Machine experience. Users have tested Steam in-home streaming with a variety of devices thus far - we've mostly seen notebook computers used to stream from larger PCs. In this way you're getting the full massive-computer experience on a smaller device, still able to use full PC controls.
"Q: Is this like other game streaming services I've heard about?
A: No, you are in complete control over the hardware on both ends and the network between them. There is no data center, no subscription, and it's completely free!
Q: Will this be fast enough for me to enjoy my favorite game?
A: This depends on your hardware, networking configuration and how fast you want it to be. It's free, so try it out and see!
Q: Can I use this to stream games across the Internet?
A: The feature is optimized for home streaming and Internet streaming is currently not supported." - SLOUKEN for Valve
At the moment external streaming - outside your home network - is not directly supported. Based on what we've seen some intrepid SHIELD users do, though, we wouldn't put it out of the equation just yet, not just because Valve says they're not all about it. Setting your PC up as a server and tapping in as if you were on the same network - that's the way SHIELD users have been rolling.
But for the beta of Steam's solution, we're seeing some mixed results. Most appear to be due to users not working with the latest drivers on their PCs or the devices they've chosen to stream to - thus is the way of things when user error is a reality. Stay tuned as the final stages are finalized - likely well before SteamOS is released in Steam Machines in the second half of this year!